海水淡化浓海水排海对海洋生态环境影响研究

Study on the Impact of the Brine Discharge from the Desalination Plant on Marine Ecological Environment

摘要: 为了解海水淡化工程排放浓海水对海洋生态环境的影响，于2021年对青岛百发海水淡化浓海水排放口邻近海域进行了4个季节的海水水质、浮游植物和浮游动物的海洋生态调查监测，采用改进内梅罗指数和生物多样性指数对海水水质环境和海洋生态环境分别进行了评价。结果表明，除无机氮和无机磷外，其余水质监测指标均符合《海水水质标准》(GB3097-1997)的第四类海水水质标准，部分监测指标达到第一类或第二类海水水质标准，无机氮和磷的污染与浓海水排放无明显关联。改进内梅罗指数评价表明海水淡化浓海水排水海域海水水质处于较清洁状态。全年4个季度调查共鉴定发现浮游植物31属49种，其中硅藻26属44种，甲藻5属5种。全年各站位浮游植物细胞丰度介于0.54~6496.00 × 10⁴ cell/m³之间，平均值为1082.62 × 10⁴ cell/m³，浮游植物细胞丰度最高峰出现在9月份。主要优势种为旋链角毛藻(Chaetoceros)、浮动弯角藻(Eucampia zodiacus)、中肋骨条藻(Skeletonema costatum)、圆筛藻(Coscinodiscus sp.)和菱形藻(Nitzschia spp.)等。全年4个季度调查共鉴定出浮游动物成体20种，其中节肢动物类15种，腔肠动物2种，原生动物、毛颚类、浮游被囊类均只有1种，另发现浮游幼虫10种。全年各站位浮游动物丰度介于5~145 ind./m³之间，平均值为85 ind./m³，生物量介于2.5~610 mg/m³之间，平均值为44 mg/m³。浮游动物群落主要优势种有洪氏纺锤水蚤(Acartia hongi)、捷氏歪水蚤(Tortanus derjugini)、刺尾歪水蚤(Tortanus spinicaudatus)、短角长腹剑水蚤(Oithona brevicornis)、异体住囊虫(Oikopleura dioica)和桡足类六肢幼虫(Nauplii larva)等，海水淡化浓盐水排放海域海洋浮游生物的种类、数量、优势种大多未发生明显变化，生物群落结构较为稳定，在短期内，海水淡化浓海水排放未对周边海域生态环境产生影响。,br> In order to understand the impact of brine discharge from seawater desalination plants on marine ecological environment, the seawater quality, phytoplankton and zooplankton were investigated and monitored in the waters adjacent to Qingdao Baifa seawater desalination plant for four seasons in 2021, and the seawater quality environment and marine ecological environment were evaluated by im-proved Nemerow index and biodiversity index respectively. The results show that, except inorganic nitrogen and inorganic phosphorus, all the other water quality monitoring indicators meet the fourth class seawater quality standard in the Standard for Seawater Quality (GB3097-1997), and some monitoring indicators reach the first class or the second class seawater standard. The pollution of inorganic nitrogen and phosphorus is not obviously related to the discharge of brine discharge. The improved Nemerow index evaluation shows that the seawater in the brine discharge area is in a relatively clean state. A total of 49 species of phytoplankton belonging to 31 genera were identified in four seasons of the year, including 44 species of bacillariophyta belonging to 26 genera and 5 species of pyrrophyta belonging to 5 genera. In the whole year, the phytoplankton cell abundance at each station ranged from 0.54 to 6496.00 × 10⁴ cell/m³, with an average of 1082.62 × 10⁴ cell/m³, and the peak of phytoplankton cell abundance appeared in September. The main dominant species are Chaetoceros, Eucampia zodiacus, Skeletonema costatum, Coscinodiscus sp., and Nitzschia spp. A total of 20 adult Zooplankton species were identified in four quarterly surveys throughout the year, including 15 species of Arthropod, 2 species of coelenterates, only 1 species of Protozoa, chaetognatha, and planktonic cysts, and 10 species of planktonic larvae. The abundance of zoo-plankton at each station was between 5 and 145 ind./m³, with an average of 85 ind./m³, and the biomass was between 2.5 and 610 mg/m³, with an average of 44 mg/m³. The main dominant species of Zooplankton community are Acartia hongi, Tortanus derjugini, Tortanus spinicaudatus, Oi-thona brevicornis, Oikopleura dioica, and Nauplii larva. The species, quantity, dominant species have not undergone significant changes, and the biological community structure is relatively stable. In the short term, the discharge of concentrated seawater from the desalination plant has not had an impact on the ecological environment of the surrounding sea areas.